Antecedent soil moisture

From Wikipedia, the free encyclopedia

A term used in surface-water hydrology in reference to runoff prediction and in process geomorphology in reference to fluvial patterns in drainage basins.

Soil retains a degree of moisture after a rainfall event. This residual water moisture affects the soil's infiltration capacity. During the next rainfall event, the infiltration capacity will cause the soil to be saturated at a different rate. The higher the level of antecedent soil moisture, the more quickly the soil becomes saturated. Once the soil is saturated, runoff will occur.